It is known that an motor control apparatus inputs summed values of a driving current corresponding to target acceleration and a disturbance compensating current corresponding to disturbance estimated by a disturbance observer into a motor, thereby performing a robust acceleration control. Regarding the motor control apparatus of the above-described type, it is known that an apparatus limits the target acceleration to a predetermined range by a limiter.
As well known, torque in a motor is saturated at a limit point. Accordingly, when the target acceleration exceeds an acceleration upper limit by the torque saturation, if any limit is not made, the torque corresponding to the target acceleration is not generated, so that the control becomes unstable. The related art copes with such problem by limiting the target acceleration.